please help!!! metallic taste in mouth

Hi,
My mother who is 74 got her metal/bitter tatse in her mouth back in Nov 04 a few days after a minor stroke which left no damage. She has that taste all the time in her mouth and when she eats, she can't taste nothing but metal or the food is bitter. She can't take it anymore. She had been to her doctor, a throat specialist and her dentist and they all can't figure it out. She is on Lipitor, cumiden(spelling?) so they stopped that for awhile with no results. Dentists said everything looked good in her mouth around her caps and partials. She was at doctor again yesterday and he told her to stop all meds for 1 week to see what happens. This is very hard for her. She had a CAT Scan and it only showed that she had some minor stroke but she has no side effects from it. This taste thing came about 3 days after she left the hospital from the stroke episode. Can anyone help????